The present invention relates to an unmanned aircraft with a propeller drive arranged in the rear or tail end of the craft for regular cruising and including, further, a releasable rocket propulsion system arranged behind the propeller and to be used for takeoff. More particularly, the invention relates to a rocket assist device for starting an unmanned aircraft wherein the rocket propulsion system provides thrust to be transmitted via thrust rods upon the fuselage of the craft to which the propulsion system pertains whereby these thrust rods are peripherally arranged between a frame carrying the rocket propulsion drive and the rear or trailing edges of wings as well as of guide surfaces of the craft.
Aircraft of the type to which the invention pertains generally are, for example, disclosed in U.S Pat. Nos. 4,471,923 and 4,410,151. They are, for example, launched from a transport container or silo, and are subsequently used, for example, for reconnaissance. Herein, thrust rods extend from the trailing edges of control surfaces as well as from the airfoils and they are secured thereto. These rods extend in rearward direction and bear against appropriate surfaces in the outer portion of a star-like arranged rocket frame. The propeller is usually started prior to takeoff and moves within the space arranged between the aircraft and the rocket frame, which space is further limited in radial direction by the aforementioned thrust rods. After the shutdown of the rocket assist propulsion device, i.e., more particularly after the thrust provided by this rocket assist device has dropped below the thrust provided by the propeller drive, the rocket assist device with frame automatically disconnects from the craft and drops to ground.